There is a recent trend in the solid laundry detergent business to chemically compact the formulation by removing at least most, and preferably all, of the zeolite. However, it has proved difficult to make these chemically compacted solid laundry detergent compositions.
The Inventors have found that the incorporation of low density silicate salt into these chemically compacted formulations enables them to be produced using traditional batch processes, and even a batch single mixer processes. Whilst it is known to incorporate silicate salt into laundry detergent compositions, it was not known, prior to the present invention, to incorporate a silicate salt that has a low bulk density and a very small weight average particle size into a formulation that has been chemically compacted by removing at least most, and preferably all, of the zeolite with the expectation that such chemically compacted detergent compositions can be produced using traditional batch processes, and even batch single mixer processes.
U.S. Pat. No. 3,472,784 relates to a free-flowing particulate detergent composition that is prepared by mixing a liquid acid form of an anionic surfactant with a water-soluble alkaline material; a silicate salt is incorporated into the exemplified detergent compositions.
U.S. Pat. No. 3,597,361 relates to a method of producing agglomerates of dry detergent ingredients; liquid sodium silicate is used in the exemplified method.
U.S. Pat. No. 3,625,902 relates to a method of producing agglomerates of detergent ingredients; liquid N-silicate and magnesium silicate are incorporated into the exemplified agglomerated home automatic dishwashing composition.
U.S. Pat. No. 4,501,499 relates to an agglomerator, which is allegedly useful for uniformly agglomerating a feed consisting of a dry mix of fumed silica and sodium carbonate and a wet mixture of non-ionic detergent and polyethylene glycol, for forming an agglomerated detergent when mixed.
U.S. Pat. No. 4,919,847 relates to a particulate detergent composition; the exemplified compositions comprise a silicate salt.
WO96/04359 relates to a process for the manufacture of detergent powders wherein LAS acid is neutralized in a fluid bed; an alkali silicate is incorporated into example composition 10 and is also described as being one of several materials that are suitable flow aids in this fluid bed process.
WO97/12956 relates to a process for making a low density detergent composition by agglomeration with a hydrated salt; silicate salts are described along with numerous other ingredients as being suitable adjunct detergent ingredients.
WO97/22685, WO98/58046, WO98/58047, WO99/00475, WO03/016453 and WO03/016454 relate to a fluid bed processes wherein crystalline or amorphous alkali metal silicates are described as being one of several materials that are suitable flow aids and/or layering agents in such fluid bed processes.
WO97/30145 relates to a process for making a low density detergent composition by agglomeration with an inorganic double salt. Silicate salt is one of numerous ingredients that are mentioned as being suitable builders that can be used in the process.
WO97/43399 relates to a process for making a low density detergent composition by agglomeration followed by dielectric heating; silicate salts are described along with numerous other ingredients as being suitable adjunct detergent ingredients.
WO98/14549 and WO98/14550 relate to non-tower processes for continuously preparing low density granular detergent compositions; crystalline layered silicate is described as one of several suitable fine powders that are used as a coating material in the process.
WO99/03966 relates to a process for making a low density detergent composition by controlling the nozzle height in a fluid bed dryer; sodium silicate is incorporated in the exemplified composition.
WO00/24859 relates to detergent particles and processes for making them; silicate salts are exemplified as a suitable ingredient for incorporation into the example detergent compositions.
WO00/37605 relates to a process for making a low bulk density detergent composition by agglomeration; silicate salts are described along with numerous other ingredients as being suitable adjunct detergent ingredients.